Self-contained photovoltaic distillation apparatus

ABSTRACT

The present disclosure describes an apparatus that may be used to generate desalinated water from a supply of untreated water using a photovoltaic cell. The front surface of the photovoltaic cell is partially enclosed to form an evaporation chamber. The front surface of the photovoltaic cell is exposed to sunlight or another light source. This exposure results in power generation by the photovoltaic cell and also heats the air in the evaporation chamber. Untreated water is subsequently introduced into the evaporation chamber. Upon contacting the heated air and the front surface of the photovoltaic cell, a portion of the untreated water evaporates to generate water vapor. The water vapor is then removed from the evaporation chamber and transported to a condensation chamber. The water vapor is cooled in the condensation chamber to yield desalinated water.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/424,473, filed on May 28, 2019, which is acontinuation-in-part of U.S. patent application Ser. No. 15/614,599,filed on Jun. 5, 2017, which is a continuation-in-part of U.S. patentapplication Ser. No. 15/379,630, filed on Dec. 15, 2016, the disclosuresof which are hereby incorporated in their entireties by reference.

BACKGROUND Field of the Invention

The present disclosure relates to a photovoltaic cell used to providepower to a distillation apparatus.

Description of the Related Art

The present disclosure relates to a photovoltaic cell used to providepower to a distillation apparatus.

The need for clean drinking water is increasingly an issue as the globalpopulation increases. Many areas that lack fresh water suitable for useas drinking water have ready access to salt water, gray water, or othercontaminated water sources. However, many such areas lack theinfrastructure or financial resources to refine water obtained from suchsources to a drinkable quality. Frequently, such areas have abundantsunlight. This unique combination has prompted the development of manysolar-powered desalination systems to produce drinkable water.

Large scale photovoltaic desalination systems utilize the powergenerated from photovoltaic cells to boil water or to power other typesof water purification systems. These systems require large up-frontcapital investment and operation of sophisticated technologies. Manyremote communities across the globe lack sufficient resources to installand operate such systems.

Small scale or personal-sized solar-powered desalination systems attemptto focus sunlight into a small evaporation chamber. These devices useair as a medium to condense water vapor. Such systems function bestunder direct sunlight without inhibition by clouds, as these conditionsare most suitable for evaporation of water. However, because the air isat a higher temperature, these conditions are least conducive tocondensing water vapor. Thus such systems are often highly inefficientor otherwise not very effective.

U.S. Patent Application Publication No. 2016/0114259 to Muller, et al.discloses a solar-powered desalination system that uses a heating unitto further heat the impure water to be purified. U.S. Pat. No. 9,834,455to Frolov, et al. discloses a solar-powered desalination system thatuses a heat exchanger to extract residual heat from the purified waterthat is then used to further heat the impure water to be purified. Theseand other disclosed solar-powered desalination systems that may besuitable for use in some small scale or personal-sized applications areencumbered by complexity, and thus such systems may not necessarily besuitable for inexpensive mass production for use in resource-poor orremote areas.

There remains a significant need for a simple, effective small scale orpersonal-sized solar-powered desalination system.

SUMMARY

The present disclosure describes an apparatus that may be used togenerate desalinated water from a supply of untreated water using aphotovoltaic cell. The front surface of the photovoltaic cell ispartially enclosed to form an evaporation chamber. The front surface ofthe photovoltaic cell is exposed to sunlight or another light source.This exposure results in power generation by the photovoltaic cell andalso heats the air in the evaporation chamber. Untreated water issubsequently introduced into the evaporation chamber. The untreatedwater may preferably be stored in an untreated water chamber beforeintroduction into the evaporation chamber. The untreated water maypreferably be introduced into the evaporation chamber using a pump. Uponcontacting the heated air and the front surface of the photovoltaiccell, a portion of the untreated water evaporates to generate watervapor. The untreated water is heated directly by contacting the heatedair and/or the front surface of the photovoltaic cell, without the useof a separate heating unit or heat exchange unit. The water vapor isthen removed from the evaporation chamber and transported to acondensation chamber. The portion of the untreated water that does notevaporate may preferably be transported back into the untreated waterchamber. The water vapor is cooled in the condensation chamber to yielddesalinated water. The water vapor may preferably be cooled using acooling plate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic of an embodiment of the disclosed apparatus,showing the mechanical components of the apparatus.

FIG. 2 shows a schematic of an embodiment of the disclosed apparatus,showing the electrical components and electrical connectivity of theapparatus.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The present disclosure describes an apparatus that may be used togenerate desalinated water from a supply of untreated water using aphotovoltaic cell.

It is well established that the front surface of a photovoltaic cellgenerates thermal energy when exposed to sunlight. By enclosing the areaaround the front surface of a photovoltaic cell, the air surroundingsaid surface may reach temperatures in excess of 140 degrees Fahrenheit.

The front surface of the photovoltaic cell is partially enclosed to forman evaporation chamber. The front surface of the photovoltaic cell isexposed to sunlight or another light or other electromagnetic radiationsource. This exposure results in power generation by the photovoltaiccell and also heats the air in the evaporation chamber. Untreated wateris subsequently introduced into the evaporation chamber. The untreatedwater may preferably be stored in an untreated water chamber beforeintroduction into the evaporation chamber. The untreated water maypreferably be introduced into the evaporation chamber using a pump. Uponcontacting the heated air and the front surface of the photovoltaiccell, a portion of the untreated water evaporates to generate watervapor. The untreated water is heated directly by contacting the heatedair and/or the front surface of the photovoltaic cell, without the useof a separate heating unit or heat exchange unit. The water vapor isthen removed from the evaporation chamber and transported to acondensation chamber. The portion of the untreated water that does notevaporate may preferably be transported back into the untreated waterchamber. The water vapor is cooled in the condensation chamber to yielddesalinated water. The water vapor may preferably be cooled using acooling plate.

The efficiency of photovoltaic cells is known to be optimized withinspecific temperature ranges. If the temperature at the surface of aphotovoltaic cell is above or below the optimum temperature range, theefficiency of the photovoltaic cell decreases. Thus, an additionaladvantage provided by the disclosed apparatus is to optimize theefficiency of the photovoltaic cell. As the photovoltaic cell is heatedby incident sunlight, it heats the air and untreated water in theevaporation chamber. The water is then collected in the condensationchamber as described. This heat transfer lowers the temperature at thesurface of the photovoltaic cell. By controlling the rate at whichuntreated water is introduced into the evaporation chamber, it ispossible to maximize the efficiency of the system by maintaining surfaceof the photovoltaic cell at its optimum operating temperature. Thisensures optimum use of available energy sources, and leads to synergybetween the generation of treated water and the operation of thephotovoltaic cell at peak efficiency.

In some preferred embodiments, electrical energy produced by thephotovoltaic cell may preferably be used to power various components ofthe apparatus.

In some preferred embodiments, some of the energy produced by thephotovoltaic cell may power the cooling plate used to condense the watervapor generated in the evaporation chamber.

In some preferred embodiments, some of the energy produced by thephotovoltaic cell may be stored in a battery or other energy storagesystem. The energy stored in a battery may be used to power othercomponents of the apparatus such as a wiper, humidistat, controller,motor, counterweight, pump, or other optional components describedherein.

In some alternate preferred embodiments, some of the energy produced bythe photovoltaic cell may be stored using a counterweight system. Energyproduced by the photovoltaic cell may be used to raise a counterweight,where the energy is stored as potential energy. The counterweight maysubsequently be lowered to release the stored potential energy whenthere is insufficient sunlight for the photovoltaic cell to operateeffectively. The energy generated by lowering the counterweight may beused to power the system at night or at other times when there isinsufficient sunlight for the photovoltaic cell to operate effectively.Some of the energy generated by lowering the counterweight may also beused to power other components of the apparatus such as a wiper,humidistat, controller, motor, pump, or other optional componentsdescribed herein. Mechanical counterweight systems are well known in theart, and the counterweight system used may be any counterweight systemthat is configured for coupling with a photovoltaic cell as describedherein.

In some embodiments, the apparatus may further comprise a wiper, whereinthe wiper may be used to remove residual deposits from the front surfaceof the photovoltaic cell. These residual deposits may be introduced viathe untreated water and may otherwise obstruct light from reaching thefront surface of the photovoltaic cell.

In some embodiments, the wiper may be operated by a motor, by using acounterweight, or by using both a motor and a counterweight. The wipermay preferably be operated according to a frequency that maximizes thedifference between the energy produced by the photovoltaic cell and theenergy consumed by operating the wiper.

In some embodiments, the apparatus may further comprise a humidistat,wherein the humidistat may be used to monitor and adjust the humidityand temperature within the evaporation chamber. The rate of introductionof untreated water may preferably be controlled by the humidistat tooptimize performance of the apparatus by maintaining high temperatureand high humidity in the evaporation chamber.

In some embodiments, the apparatus may further comprise two or moreaerators, wherein at least one aerator may be used to introduce airbubbles into the untreated water stream entering the evaporation chamberand at least one other aerator may be used to allow excess air or othergases to exit the evaporation chamber to maintain equilibrium and avoida buildup of pressure. The introduction of air bubbles into theuntreated water stream will increase the surface area of contact betweenthe heated air in the evaporation chamber and the untreated water. Thisresults in a higher rate of evaporation.

FIG. 1 illustrates an embodiment 100 of the disclosed apparatus, showinga schematic depiction of the mechanical components of the embodiment100. Evaporation Chamber 101 is situated between Photovoltaic Cell 102and Glass Plate 103. Untreated Water Chamber 104 contains untreatedwater. Photovoltaic Cell 102 is exposed to sunlight. Subsequently, theair within Evaporation Chamber 101 is heated both by contact with thefront surface of Photovoltaic Cell 102 and directly by the enteringsunlight. The untreated water in Untreated Water Chamber 104 is thenintroduced into Evaporation Chamber 101 using Pump 105. Upon contactingthe heated air and the front surface of Photovoltaic Cell 102, a portionof untreated water evaporates in Evaporation Chamber 101 to generatewater vapor. The water vapor diffuses into Condensation Chamber 106 andsubsequently condenses on Cooling Plate 107. The portion of untreatedwater that does not evaporate is transported back into Untreated WaterChamber 104 via Recirculation Reservoir 108. Desalinated water iscollected in Treated Water Chamber 109. A sensor connected to Humidistat110 monitors the humidity and temperature within Evaporation Chamber 101and transmits this data to Humidistat 110. Humidistat 110 uses the dataobtained from the sensor to adjust the humidity and temperature asnecessary to optimize performance of the apparatus by maintaining hightemperature and high humidity in Evaporation Chamber 101. Aerators 111introduce air bubbles into the untreated water stream enteringEvaporation Chamber 101 and allow excess air or other gases to exitEvaporation Chamber 101 to maintain equilibrium and avoid a buildup ofpressure. Wiper 112 is used to remove residual deposits from the frontsurface of Photovoltaic Cell 102. Wiper 112 is operated by andCounterweight 113. Counterweight 113 is also used to store potentialenergy that is used to operate the apparatus when sunlight isunavailable. Counterweight 113 is connected to a motor (not shown).Photovoltaic Cell 102 is offset from the vertical plane by an angle of θdegrees, where θ may preferably be between about 20 and 60, morepreferably between about 30 and 45, and even more preferably betweenabout 35 and 40, and most preferably about 36 degrees.

FIG. 2 illustrates an embodiment 200 of the disclosed apparatus, showinga schematic depiction of the electrical components and electricalconnectivity of the embodiment 200. Photovoltaic Cell 202 is exposed tosunlight to generate energy. Some of the energy generated is transferredto Battery 215 via Charge Control Unit 216. Battery 215 stores theenergy transferred thereto for use in powering other components of theapparatus. Charge Control Unit 216 manages the distribution of energyfrom Battery 215 to the remaining components of the apparatus, includingPump 205, Cooling Plate 207, Humidistat 210, Aerators 211, Wiper 212,and Counterweight 213. Counterweight 213 is connected to a motor (notshown). Pump 205 is used to introduce untreated water from UntreatedWater Chamber 204 to the evaporation chamber (not shown). Humidistat 210may be turned on and off using Humidistat Switch 214.

EXAMPLE

Untreated salt water with 35 ppt salt was generated using Instant Ocean.Power generated by the photovoltaic cell was used by a controller and 12volt DC water pump to pump untreated water into the evaporation chamber.A cooling plate comprising thermoelectric modules situated between twocopper plates was employed in the condensation chamber. When the coolingplate was exposed to current, the thermoelectric modules rendered onecopper plate cool and the other copper plate hot. The thermoelectricmodules were configured so that the cool plate was on the inside of thecondensation chamber. The cool plate was used to condense water vaporgenerated in the evaporation chamber. The salinity of the condensedwater vapor was measured and determined to be 1.1 ppt.

The previous description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the inventiondisclosed herein. Although the various inventive aspects are disclosedin the context of certain illustrated embodiments, implementations, andexamples, it should be understood by those skilled in the art that theinvention extends beyond the specifically disclosed embodiments to otheralternative embodiments and/or uses of the invention and obviousmodifications and equivalents thereof. In addition, while a number ofvariations of various inventive aspects have been shown and described indetail, other modifications that are within their scope will be readilyapparent to those skilled in the art based upon reviewing thisdisclosure. It should be also understood that the scope of thisdisclosure includes the various combinations or sub-combinations of thespecific features and aspects of the embodiments disclosed herein, suchthat the various features, modes of implementation, and aspects of thedisclosed subject matter may be combined with or substituted for oneanother. The generic principles defined herein may be applied to otherembodiments without departing from the spirit or scope of thedisclosure. Thus, the present disclosure is not intended to be limitedto the embodiments shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

Similarly, the disclosure is not to be interpreted as reflecting anintent that any claim set forth below requires more features than areexpressly recited in that claim. Rather, as the following claimsreflect, inventive aspects may reside in a combination of fewer than allfeatures of any single foregoing disclosed embodiment.

Each of the foregoing and various aspects, together with those set forthin the claims and summarized above or otherwise disclosed herein,including the figures, may be combined without limitation to form claimsfor a device, apparatus, system, method of manufacture, and/or method ofuse.

All references cited herein are hereby expressly incorporated byreference.

What is claimed is:
 1. A distillation apparatus comprising: a. aphotovoltaic cell that has a front surface configured for exposure tolight, wherein the front surface of the photovoltaic cell is heated whenit is exposed to light; b. an evaporation chamber that contains airtherein, wherein the front surface of the photovoltaic cell forms oneside of the evaporation chamber, and wherein the air is heated when thefront surface of the photovoltaic cell is exposed to light; c. acondensation chamber that is situated adjacent to the evaporationchamber; and d. an untreated water chamber that contains untreatedwater, wherein the untreated water chamber is operationally connected tothe evaporation chamber; wherein the apparatus is configured to heat theuntreated water without the use of a heating unit or a heat exchangeunit; wherein the apparatus does not include a heating unit or a heatexchange unit; wherein the untreated water is heated by the heated airand the heated front surface of the photovoltaic cell; and wherein theapparatus is used to generate treated water from the untreated waterthat is heated using the apparatus.
 2. The distillation apparatus ofclaim 1, wherein the apparatus is sealed to prevent a substantial influxor outflow of air from the apparatus.
 3. The distillation apparatus ofclaim 1, wherein the condensation chamber further comprises a coolingplate.
 4. The distillation apparatus of claim 2, wherein thecondensation chamber further comprises a cooling plate.
 5. Thedistillation apparatus of claim 4 further comprising an untreated waterchamber, wherein untreated water stored in the untreated water chamberis introduced into the evaporation chamber by a pump.
 6. Thedistillation apparatus of claim 5 further comprising a treated waterchamber, wherein the treated water chamber is used to collect treatedwater.
 7. The distillation apparatus of claim 6, wherein untreated waterenters the evaporation chamber substantially close to the top of theevaporation chamber, and wherein untreated water that does not evaporateis collected in a recirculation reservoir situated substantially closeto the bottom of the evaporation chamber, wherein said untreated waterthat does not evaporate is transported from the recirculation reservoirto the untreated water chamber.
 8. The distillation apparatus of claim4, wherein the cooling plate comprises one or more thermoelectricmodules situated between two metal plates.
 9. The distillation apparatusof claim 8, wherein the metal plates are copper plates.
 10. Thedistillation apparatus of claim 7, wherein the untreated water comprisessalt water or gray water.
 11. The distillation apparatus of claim 7further comprising a battery, wherein the battery is configured to storeenergy generated by the photovoltaic cell.
 12. The distillationapparatus of claim 7 further comprising a counterweight system, whereinthe battery is configured to store energy generated by the photovoltaiccell.
 13. The distillation apparatus of claim 7 further comprising ahumidistat, wherein the humidistat is configured to control the rate atwhich untreated water enters the evaporation chamber.
 14. Thedistillation apparatus of claim 7 further comprising two or moreaerators, wherein at least one aerator is used to introduce air bubblesinto the stream of untreated water that enters the evaporation chamberand at least one other aerator is used to allow excess air or othergases to exit the evaporation chamber to maintain equilibrium and avoida buildup of pressure.
 15. The distillation apparatus of claim 7 furthercomprising a wiper, wherein the wiper is configured to clean the frontsurface of the photovoltaic cell at a specified frequency.
 16. Thedistillation apparatus of claim 14, wherein the wiper is operated by amotor, by using the counterweight, or by using both a motor and thecounterweight.
 17. The distillation apparatus of claim 11 furthercomprising a humidistat, wherein the humidistat is configured to controlthe rate at which untreated water enters the evaporation chamber. 18.The distillation apparatus of claim 16 further comprising two or moreaerators, wherein at least one aerator is used to introduce air bubblesinto the stream of untreated water that enters the evaporation chamberand at least one other aerator is used to allow excess air or othergases to exit the evaporation chamber to maintain equilibrium and avoida buildup of pressure.
 19. The distillation apparatus of claim 17further comprising a wiper, wherein the wiper is configured to clean thefront surface of the photovoltaic cell at a specified frequency.